As extreme weather events linked to the climate crisis continue, 2023 is likely to be the hottest year since at least 1850, when reliable temperature records began. 1850 is also the year that is usually used as a reference to explain the origin of the problem, which is fundamentally linked to fossil fuels, which are mainly responsible for greenhouse gas emissions. These gases accumulate over decades or centuries in the atmosphere and cause global warming. It is from the Industrial Revolution that human beings begin to use coal, oil and gas on a large scale, which have triggered the climate crisis. But not all of humanity is equally responsible. "Contributions to climate change are uneven," warns a report by the United Nations Environment Programme (UNEP) published on Monday. "A minority of countries have contributed the majority of emissions," the study said.
The authors, when talking about historical responsibilities, point directly to the richest and most developed nations: "Together, the United States of America and the European Union contributed nearly one-third of total cumulative emissions [of carbon dioxide, the main greenhouse gas] from 1850 to 2021." Both powers accumulate, specifically, 32% of CO₂ —19%, the United States; 13%, the 27 members of the EU, have been expelled in these 171 years. The third major player in this story is China, which has already generated another 13% of the world's carbon dioxide since 1850.
The data comes from UNEP's Emissions Gap Report, which warns that greenhouse gases continue to rise (in 2022 they grew by another 1.2%). The authors highlight that progress has been made since the Paris Agreement was signed in 2015, although the climate plans that the world's nations have in place still lead to warming of between 2.5 and 2.9 degrees Celsius, well above the safety levels set in that pact eight years ago.
This is the 1850th edition of the gap report, which year after year has been providing an increasingly clear picture "of past and present emissions," explains Joeri Rogelj, one of its lead authors and professor of climate science and politics at Imperial College London. "Not only in terms of how many emissions are being produced globally, but also by who and what their effect has been on global warming." But this year is the first time the study has delved into countries' historical contributions to global warming since <>. "This information helps us better understand the current situation in which countries need to make decisions on how to solve the climate crisis," he adds.
If we look back, it is clear that the historical culprits are to be found in the G-20, whose members accumulate almost 80% of all the carbon dioxide expelled between 1850 and 2021. In addition to CO₂ emissions, the report adds another indicator: the contribution to global warming, which is less precise than in the case of carbon dioxide, but which also includes the estimation of cumulative emissions of other greenhouse gases such as methane, nitrous oxide and fluorinated gases. And the U.S. is once again first, with 17%. It is followed in this ranking by China (12%), the EU (10%), Russia (6%) and India (5%).
But the picture changes when you look at current emissions. China has been by far the world's leading emitter for two decades now. In 2021, according to the UNEP report, it was responsible for 30% of all greenhouse gases. It is followed by the US (11%), India (7%), the EU (7%) and Russia (5%).
Another useful indicator for determining responsibility for climate change is emissions by population. In this case, and only in the group of large emitters, the United States and Russia, both with around 15 tons per capita in 2021, top the list. Next is China, with just over 10 tonnes per inhabitant (the world average is 6.5).
China is indeed behind the United States, but while the US economy has reduced its per capita emissions in the last 20 years (from 22.3 tonnes to 15.3 tonnes), the Asian country continues to increase them and has more than doubled them in the same period, from 3.6 to 10.2. What experts fear is that they will continue to grow in the case of China and other developing nations such as India, the most populous nation on the planet. This seriously compromises the international fight against climate change.
"To get out of poverty and develop, people need clean and safe energy," says Rogelj. "Historically, the main way to provide energy was fossil fuels, and developed countries have used them a lot, which generated a lot of greenhouse gas emissions and global warming," he adds. "Poorer countries have an inalienable right to develop and they need energy to do so," he said, "but fortunately today we also have low-carbon energy options that are cheap." "With the right support, poorer countries should be able to avoid the climate mistakes of the past," Rogelj concludes.
UNEP highlights that "an increasing number of countries have peaked" emissions and have reduced "their absolute emissions for more than 10 years." In other words, it has already reached its peak. 36 countries are at that point, of which 22 are members of the European Union, while another eight are high-income countries: Australia, the US, Israel, Japan, Norway, the UK, Switzerland and Ukraine. Six other middle-income countries have also done so: Albania, Cuba, Jamaica, Mexico, North Macedonia and South Africa.
Reaching that peak as soon as possible and then drastically reducing emissions is what is needed to meet the Paris Agreement. This pact, signed in the French capital in 2015, sets as its main objective that the increase in global temperature remains below two degrees by the end of the century, and as far as possible at 1.5 degrees, always with respect to pre-industrial levels. At the moment, warming is around 1.2 degrees and in the best-case scenario, scientists suggest that this barrier of 1.5 degrees will be exceeded and then fallen. To do this, the first step is to reduce emissions by 42% by 2030. But the climate plans of the nearly 200 countries that are in the Paris Agreement will lead to a reduction of between 2% and 9%, the UNEP report estimates. To stay below 2 degrees of warming, the cut in emissions in 2030 would have to be 28%, also far from what climate plans are now proposing.
Response time is running out, although countries need to update their climate plans upwards periodically. At the COP30 climate summit that kicks off on November 28 in Dubai, the first major assessment will be made and a call will be made for tougher emissions cuts. By 2025, all nations will have to submit their new pledges. "There is no person or economy on the planet that is not affected by climate change, so we must stop setting unwanted records on greenhouse gas emissions, global maximum temperatures and extreme weather," Inger Andersen, UNEP's executive director, said on Monday.
UN Secretary-General António Guterres has urged countries to strengthen their climate plans to "cover the entire economy and chart a course to end fossil fuels". Specifically, he called on nations meeting in Dubai to commit "to tripling renewable energy capacity, doubling energy efficiency and bringing clean energy to all by 2030". And to "phase out fossil fuels, with a clear timeframe aligned with the 1.5-degree limit."
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